perf(parser): optimize browser parsing hot paths

packages/parser/src/browser/line.test.ts

@@ -20,7 +20,7 @@ describe('LINE browser-safe text parser', () => {
       '03:05pm\tBob\t[Photo]',
       '03:06pm\t\tAlice joined the group',
       '',
-    ].join('\n')
+    ].join('\r\n')
 
     assert.equal(detectLineText(content, '[LINE] Project Team.txt'), true)
     assert.equal(detectLineText('2024/01/02 03:04 - Alice: hello', '与Alice的 WhatsApp 聊天.txt'), false)
@@ -85,4 +85,25 @@ describe('LINE browser-safe text parser', () => {
     assert.equal(result.messages.length, 1002)
     assert.ok(checks > 10)
   })
+
+  it('classifies prefixed media, links, locations, and system messages', async () => {
+    const content = [
+      '[LINE] Chat history in Project Team',
+      'Saved on: 2024/01/03 09:00',
+      '',
+      '2024.01.02 Tuesday',
+      '03:04\tAlice\t[File] report.pdf',
+      '03:05\tAlice\thttps://example.com',
+      '03:06\tAlice\t[null] https://maps.google.com/example',
+      '03:07\tAlice\tBob left the group',
+      '',
+    ].join('\n')
+
+    const result = await parseLineText(content, '[LINE] Project Team.txt')
+
+    assert.deepEqual(
+      result.messages.map((message) => message.type),
+      [MessageType.FILE, MessageType.LINK, MessageType.LOCATION, MessageType.SYSTEM]
+    )
+  })
 })

packages/parser/src/browser/line.ts

@@ -75,6 +75,7 @@ const SPECIAL_MESSAGE_TYPES: Record<string, MessageType> = {
   '[記事本]': MessageType.TEXT,
   '[ノート]': MessageType.TEXT,
 }
+const SPECIAL_MESSAGE_TYPE_ENTRIES = Object.entries(SPECIAL_MESSAGE_TYPES)
 
 export function detectLineText(head: string, fileName: string): boolean {
   const basename = getBasename(fileName)
@@ -90,20 +91,21 @@ export async function parseLineText(
   fileName: string,
   options: LineTextParseOptions = {}
 ): Promise<LineTextParseResult> {
-  const lines = content.split('\n').map((line) => line.replace(/\r$/, ''))
+  const lines = content.split('\n')
   const memberMap = new Map<string, ParsedMember>()
   const messages: ParsedMessage[] = []
-  const header = lines.length > 0 ? extractNameFromHeader(lines[0].trim()) : null
+  const header = lines.length > 0 ? extractNameFromHeader(lines[0].replace(/\r$/, '').trim()) : null
   const chatName = header?.name ?? extractNameFromFileName(fileName)
   let currentDate: Date | null = null
   let lastMessage: ParsedMessage | null = null
   let quotedMultiline = false
   let lineIndex = header ? 3 : 0
   let useTabSeparator = Boolean(header)
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 1000)
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
 
   if (!header) {
-    for (const line of lines) {
+    for (const rawLine of lines) {
+      const line = rawLine.replace(/\r$/, '')
       if (TAB_MESSAGE_PATTERN.test(line)) {
         useTabSeparator = true
         break
@@ -117,7 +119,7 @@ export async function parseLineText(
 
   for (; lineIndex < lines.length; lineIndex += 1) {
     options.checkCancelled?.()
-    const line = lines[lineIndex]
+    const line = lines[lineIndex].replace(/\r$/, '')
     const date = parseDateLine(line)
     if (date) {
       currentDate = date
@@ -262,7 +264,7 @@ function parseTime(timeText: string): { hours: number; minutes: number } {
 }
 
 function detectMessageType(content: string): MessageType {
-  for (const [pattern, type] of Object.entries(SPECIAL_MESSAGE_TYPES)) {
+  for (const [pattern, type] of SPECIAL_MESSAGE_TYPE_ENTRIES) {
     if (content === pattern || content.startsWith(pattern)) return type
   }
   if (content.startsWith('[null]') && content.includes('maps.google.com')) return MessageType.LOCATION

packages/parser/src/browser/qq.ts

@@ -45,7 +45,7 @@ export async function parseQqText(
 ): Promise<QqTextParseResult> {
   const accumulator = new QqTextAccumulator(fileName)
   const lines = content.split('\n')
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 1000)
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
 
   for (let index = 0; index < lines.length; index += 1) {
     options.checkCancelled?.()

packages/parser/src/browser/telegram.ts

@@ -65,7 +65,7 @@ export async function scanTelegramChatsJson(
   options.checkCancelled?.()
   const value = parseTelegramFullExport(content)
   const chats: TelegramChatInfo[] = []
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 100)
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
 
   for (let index = 0; index < value.chats.list.length; index += 1) {
     options.checkCancelled?.()
@@ -124,7 +124,7 @@ async function parseTelegramChat(
   const memberMap = new Map<string, ParsedMember>()
   const messages: ParsedMessage[] = []
   const chatType = mapChatType(value.type)
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 1000)
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
 
   for (let index = 0; index < value.messages.length; index += 1) {
     options.checkCancelled?.()

packages/parser/src/browser/weflow.test.ts

@@ -0,0 +1,45 @@
+import assert from 'node:assert/strict'
+import { describe, it } from 'node:test'
+import { ChatType, KNOWN_PLATFORMS, MessageType } from '@openchatlab/shared-types'
+
+import { parseWeFlowJson } from './weflow'
+
+describe('WeFlow browser-safe JSON parser', () => {
+  it('parses messages and only reports intermediate progress at cooperative yield points', async () => {
+    const progress: Array<{ progress: number; messagesProcessed: number }> = []
+    const content = JSON.stringify({
+      weflow: { version: '1.0.0' },
+      session: { wxid: 'group@chatroom', displayName: 'Project Team', type: '群聊' },
+      messages: Array.from({ length: 5 }, (_, index) => ({
+        localId: index + 1,
+        createTime: 1704164645 + index,
+        type: '文本消息',
+        content: `message ${index}`,
+        isSend: index === 0 ? 1 : 0,
+        senderUsername: `member-${index % 2}`,
+        senderDisplayName: `Member ${index % 2}`,
+      })),
+    })
+
+    const result = await parseWeFlowJson(content, 'project.json', {
+      yieldEvery: 2,
+      onProgress: (value) => progress.push(value),
+    })
+
+    assert.deepEqual(result.meta, {
+      name: 'Project Team',
+      platform: KNOWN_PLATFORMS.WECHAT,
+      type: ChatType.GROUP,
+      groupId: 'group@chatroom',
+      groupAvatar: undefined,
+      ownerId: 'member-0',
+    })
+    assert.equal(result.messages.length, 5)
+    assert.equal(result.messages[0]?.type, MessageType.TEXT)
+    assert.deepEqual(
+      progress.map((value) => value.messagesProcessed),
+      [2, 4, 5]
+    )
+    assert.equal(progress.at(-1)?.progress, 1)
+  })
+})

packages/parser/src/browser/weflow.ts

@@ -61,10 +61,16 @@ export async function parseWeFlowJson(
   const messageValues = Array.isArray(value.messages) ? value.messages : []
   const members = new Map<string, MemberState>()
   const messages: ParsedMessage[] = []
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
   let ownerId: string | undefined
 
   for (let index = 0; index < messageValues.length; index += 1) {
-    await cooperate(index, options)
+    options.checkCancelled?.()
+    if (index > 0 && index % yieldEvery === 0) {
+      options.onProgress?.({ progress: index / messageValues.length, messagesProcessed: messages.length })
+      await new Promise<void>((resolve) => setTimeout(resolve, 0))
+      options.checkCancelled?.()
+    }
     const message = messageValues[index]
     if (!isRecord(message)) continue
 
@@ -92,10 +98,6 @@ export async function parseWeFlowJson(
       type: convertMessageType(stringValue(message.type)),
       content: normalizeContent(message.content),
     })
-    options.onProgress?.({
-      progress: messageValues.length === 0 ? 1 : (index + 1) / messageValues.length,
-      messagesProcessed: messages.length,
-    })
   }
 
   options.checkCancelled?.()
@@ -183,12 +185,3 @@ function stringValue(value: unknown): string | undefined {
 function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === 'object' && value !== null && !Array.isArray(value)
 }
-
-async function cooperate(index: number, options: WeFlowJsonParseOptions): Promise<void> {
-  options.checkCancelled?.()
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 1000)
-  if (index > 0 && index % yieldEvery === 0) {
-    await new Promise<void>((resolve) => setTimeout(resolve, 0))
-    options.checkCancelled?.()
-  }
-}

packages/parser/src/browser/whatsapp.ts

@@ -108,7 +108,7 @@ export async function parseWhatsAppText(
 ): Promise<WhatsAppTextParseResult> {
   const accumulator = new WhatsAppTextAccumulator(fileName)
   const lines = content.split('\n')
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 1000)
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
 
   for (let index = 0; index < lines.length; index += 1) {
     options.checkCancelled?.()

packages/parser/src/formats/instagram-native.test.ts

@@ -0,0 +1,62 @@
+import assert from 'node:assert/strict'
+import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { describe, it } from 'node:test'
+import { MessageType } from '@openchatlab/shared-types'
+
+import { detectFormat, parseFileSync } from '../index'
+
+function encodeInstagramText(value: string): string {
+  return Buffer.from(value, 'utf8').toString('latin1')
+}
+
+describe('Instagram native parser', () => {
+  it('decodes Instagram text and classifies system messages', async () => {
+    const directory = mkdtempSync(join(tmpdir(), 'chatlab-instagram-parser-'))
+    try {
+      const filePath = join(directory, 'message_1.json')
+      writeFileSync(
+        filePath,
+        JSON.stringify({
+          participants: [{ name: encodeInstagramText('小明') }, { name: encodeInstagramText('小红') }],
+          messages: [
+            {
+              sender_name: encodeInstagramText('小红'),
+              timestamp_ms: 2000,
+              content: 'Alice added Bob to the group',
+              is_geoblocked_for_viewer: false,
+            },
+            {
+              sender_name: encodeInstagramText('小明'),
+              timestamp_ms: 1000,
+              content: encodeInstagramText('你好'),
+              is_geoblocked_for_viewer: false,
+            },
+          ],
+          title: encodeInstagramText('小红'),
+          thread_path: 'inbox/example',
+        }),
+        'utf8'
+      )
+
+      assert.equal(detectFormat(filePath)?.id, 'instagram-native')
+      const result = await parseFileSync(filePath)
+
+      assert.equal(result.meta.name, '小红')
+      assert.deepEqual(
+        result.messages.map((message) => ({
+          sender: message.senderAccountName,
+          type: message.type,
+          content: message.content,
+        })),
+        [
+          { sender: '小明', type: MessageType.TEXT, content: '你好' },
+          { sender: '小红', type: MessageType.SYSTEM, content: 'Alice added Bob to the group' },
+        ]
+      )
+    } finally {
+      rmSync(directory, { recursive: true, force: true })
+    }
+  })
+})

packages/parser/src/formats/instagram-native.ts

@@ -106,6 +106,8 @@ interface InstagramData {
 
 // ==================== 辅助函数 ====================
 
+const UTF8_DECODER = new TextDecoder('utf-8')
+
 /**
  * 解码 Instagram 特殊编码的文本
  * Instagram 将 UTF-8 字节按 Latin-1 编码后存储
@@ -118,7 +120,7 @@ function decodeInstagramText(text: string): string {
       bytes[i] = text.charCodeAt(i)
     }
     // 用 UTF-8 解码
-    return new TextDecoder('utf-8').decode(bytes)
+    return UTF8_DECODER.decode(bytes)
   } catch {
     return text // 解码失败则返回原文
   }
@@ -135,23 +137,24 @@ function extractNameFromFilePath(filePath: string): string {
 /**
  * 判断是否为系统消息
  */
+const SYSTEM_MESSAGE_PATTERNS = [
+  'You created the group',
+  'created the group',
+  'added',
+  'to the group',
+  'left the group',
+  'removed',
+  'named the group',
+  'changed the group photo',
+  'Reacted',
+  'sent an attachment',
+  'liked a message',
+  'changed the theme',
+  'set the nickname',
+]
+
 function isSystemMessage(content: string): boolean {
-  const systemPatterns = [
-    'You created the group',
-    'created the group',
-    'added',
-    'to the group',
-    'left the group',
-    'removed',
-    'named the group',
-    'changed the group photo',
-    'Reacted',
-    'sent an attachment',
-    'liked a message',
-    'changed the theme',
-    'set the nickname',
-  ]
-  return systemPatterns.some((p) => content.includes(p))
+  return SYSTEM_MESSAGE_PATTERNS.some((pattern) => content.includes(pattern))
 }
 
 /**
@@ -286,11 +289,11 @@ async function* parseInstagram(options: ParseOptions): AsyncGenerator<ParseEvent
   const members = Array.from(memberMap.values())
   yield { type: 'members', data: members }
 
-  // 处理消息（Instagram 消息是逆序的，需要反转）
-  const reversedMessages = [...data.messages].reverse()
+  // Instagram 消息是逆序的；从尾部遍历即可按时间正序输出，避免复制整份消息数组。
   const messageBatch: ParsedMessage[] = []
 
-  for (const msg of reversedMessages) {
+  for (let index = data.messages.length - 1; index >= 0; index -= 1) {
+    const msg = data.messages[index]
     const senderName = decodeInstagramText(msg.sender_name)
     const timestamp = Math.floor(msg.timestamp_ms / 1000) // 毫秒转秒
     const type = detectMessageType(msg)
@@ -321,7 +324,7 @@ async function* parseInstagram(options: ParseOptions): AsyncGenerator<ParseEvent
 
       const progress = createProgress(
         'parsing',
-        Math.floor((messagesProcessed / reversedMessages.length) * totalBytes),
+        Math.floor((messagesProcessed / data.messages.length) * totalBytes),
         totalBytes,
         messagesProcessed,
         `已处理 ${messagesProcessed} 条消息...`

packages/web-runtime/src/import/chatlab-parser.test.ts

@@ -23,7 +23,16 @@ describe('ChatLab browser parser', () => {
         meta: { name: 'Fixture', platform: 'wechat', type: 'group', ownerId: 'alice' },
         members: [{ platformId: 'alice', accountName: 'Alice' }],
         messages: [
-          { sender: 'alice', accountName: 'Alice', timestamp: 1, type: 0, content: 'hello' },
+          {
+            sender: 'alice',
+            accountName: 'Alice',
+            groupNickname: 'A',
+            timestamp: 1,
+            type: 0,
+            content: 'hello',
+            platformMessageId: 'message-1',
+            replyToMessageId: 'message-0',
+          },
           { sender: 'bob', accountName: 'Bob', timestamp: 2, type: 0, content: null },
         ],
       })
@@ -44,6 +53,16 @@ describe('ChatLab browser parser', () => {
       ['alice', 'bob']
     )
     assert.equal(parsed.messages.length, 2)
+    assert.deepEqual(parsed.messages[0], {
+      senderPlatformId: 'alice',
+      senderAccountName: 'Alice',
+      senderGroupNickname: 'A',
+      timestamp: 1,
+      type: 0,
+      content: 'hello',
+      platformMessageId: 'message-1',
+      replyToMessageId: 'message-0',
+    })
     assert.equal(parsed.messages[1].senderPlatformId, 'bob')
   })
 
@@ -114,4 +133,45 @@ describe('ChatLab browser parser', () => {
       /cancelled/
     )
   })
+
+  it('throttles JSON and JSONL progress updates to cooperative yield points', async () => {
+    const messages = Array.from({ length: 5 }, (_, index) => ({
+      sender: `member-${index}`,
+      accountName: `Member ${index}`,
+      timestamp: index + 1,
+      type: 0,
+      content: 'message',
+    }))
+    const jsonProgress: number[] = []
+    await parseChatLabSource(
+      source(
+        'progress.json',
+        JSON.stringify({
+          chatlab: { version: '1', exportedAt: 1 },
+          meta: { name: 'Progress', platform: 'unknown', type: 'group' },
+          messages,
+        })
+      ),
+      { yieldEvery: 2, onProgress: (value) => jsonProgress.push(value.messagesProcessed) }
+    )
+
+    const jsonlProgress: number[] = []
+    await parseChatLabSource(
+      source(
+        'progress.jsonl',
+        [
+          JSON.stringify({
+            _type: 'header',
+            chatlab: { version: '1', exportedAt: 1 },
+            meta: { name: 'Progress', platform: 'unknown', type: 'group' },
+          }),
+          ...messages.map((message) => JSON.stringify({ _type: 'message', ...message })),
+        ].join('\n')
+      ),
+      { yieldEvery: 2, onProgress: (value) => jsonlProgress.push(value.messagesProcessed) }
+    )
+
+    assert.deepEqual(jsonProgress, [2, 4, 5])
+    assert.deepEqual(jsonlProgress, [0, 2, 4, 5])
+  })
 })

packages/web-runtime/src/import/chatlab-parser.ts

@@ -116,17 +116,23 @@ async function parseJson(content: string, options: ParseChatLabSourceOptions): P
   }
 
   const messages: BrowserParsedMessage[] = []
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
   for (let index = 0; index < root.messages.length; index += 1) {
-    await cooperate(index, options)
+    options.checkCancelled?.()
+    if (index > 0 && index % yieldEvery === 0) {
+      options.onProgress?.({
+        stage: 'parsing',
+        progress: index / root.messages.length,
+        messagesProcessed: messages.length,
+      })
+      await new Promise<void>((resolve) => setTimeout(resolve, 0))
+      options.checkCancelled?.()
+    }
     messages.push(parseMessage(root.messages[index], `messages[${index}]`))
-    options.onProgress?.({
-      stage: 'parsing',
-      progress: root.messages.length === 0 ? 1 : (index + 1) / root.messages.length,
-      messagesProcessed: index + 1,
-    })
   }
 
   options.checkCancelled?.()
+  options.onProgress?.({ stage: 'parsing', progress: 1, messagesProcessed: messages.length })
   return {
     formatId: 'chatlab',
     meta,
@@ -142,6 +148,7 @@ async function parseJsonl(content: string, options: ParseChatLabSourceOptions):
   let firstRecordSeen = false
   let cursor = 0
   let lineNumber = 0
+  const yieldEvery = Math.max(1, options.yieldEvery ?? 5000)
 
   while (cursor <= content.length) {
     const nextBreak = content.indexOf('\n', cursor)
@@ -149,9 +156,18 @@ async function parseJsonl(content: string, options: ParseChatLabSourceOptions):
     const line = content.slice(cursor, end).replace(/\r$/, '').trim()
     lineNumber += 1
     cursor = nextBreak === -1 ? content.length + 1 : nextBreak + 1
+    options.checkCancelled?.()
+    if (lineNumber > 0 && lineNumber % yieldEvery === 0) {
+      options.onProgress?.({
+        stage: 'parsing',
+        progress: content.length === 0 ? 1 : Math.min(1, cursor / content.length),
+        messagesProcessed: messages.length,
+      })
+      await new Promise<void>((resolve) => setTimeout(resolve, 0))
+      options.checkCancelled?.()
+    }
     if (!line || line.startsWith('#')) continue
 
-    await cooperate(lineNumber, options)
     let value: unknown
     try {
       value = JSON.parse(line)
@@ -182,11 +198,6 @@ async function parseJsonl(content: string, options: ParseChatLabSourceOptions):
         break
       case 'message':
         messages.push(parseMessage(value, `line ${lineNumber}`))
-        options.onProgress?.({
-          stage: 'parsing',
-          progress: content.length === 0 ? 1 : Math.min(1, cursor / content.length),
-          messagesProcessed: messages.length,
-        })
         break
       default:
         throw new WebRuntimeError('INVALID_IMPORT_FILE', `Unknown ChatLab JSONL record type at line ${lineNumber}`)
@@ -244,16 +255,20 @@ function parseMessage(value: unknown, path: string): BrowserParsedMessage {
   const content = value.content
   if (content !== null && typeof content !== 'string') throw invalidField(`${path}.content`, 'must be a string or null')
 
-  return omitUndefined({
+  const message: BrowserParsedMessage = {
     senderPlatformId: sender,
     senderAccountName: optionalString(value.accountName, `${path}.accountName`) ?? sender,
-    senderGroupNickname: optionalString(value.groupNickname, `${path}.groupNickname`),
     timestamp,
     type,
     content,
-    platformMessageId: optionalString(value.platformMessageId, `${path}.platformMessageId`),
-    replyToMessageId: optionalString(value.replyToMessageId, `${path}.replyToMessageId`),
-  })
+  }
+  const senderGroupNickname = optionalString(value.groupNickname, `${path}.groupNickname`)
+  const platformMessageId = optionalString(value.platformMessageId, `${path}.platformMessageId`)
+  const replyToMessageId = optionalString(value.replyToMessageId, `${path}.replyToMessageId`)
+  if (senderGroupNickname !== undefined) message.senderGroupNickname = senderGroupNickname
+  if (platformMessageId !== undefined) message.platformMessageId = platformMessageId
+  if (replyToMessageId !== undefined) message.replyToMessageId = replyToMessageId
+  return message
 }
 
 function mergeInferredMembers(
@@ -272,15 +287,6 @@ function mergeInferredMembers(
   return [...byId.values()]
 }
 
-async function cooperate(index: number, options: ParseChatLabSourceOptions): Promise<void> {
-  options.checkCancelled?.()
-  const yieldEvery = Math.max(1, options.yieldEvery ?? 1000)
-  if (index > 0 && index % yieldEvery === 0) {
-    await new Promise<void>((resolve) => setTimeout(resolve, 0))
-    options.checkCancelled?.()
-  }
-}
-
 function firstMeaningfulLine(content: string): string | undefined {
   return content
     .split(/\r?\n/)

packages/web-runtime/src/import/wasm-parser.test.ts

@@ -34,9 +34,12 @@ describe('browser Rust WASM parser', () => {
         {
           sender: 'alice',
           accountName: 'Alice',
+          groupNickname: 'A',
           timestamp: 1,
           type: 0,
           content: 'hello chatlab',
+          platformMessageId: 'message-1',
+          replyToMessageId: 'message-0',
         },
       ],
     })
@@ -54,6 +57,16 @@ describe('browser Rust WASM parser', () => {
       chatlab.messages.map((message) => message.content),
       ['hello chatlab']
     )
+    assert.deepEqual(chatlab.messages[0], {
+      senderPlatformId: 'alice',
+      senderAccountName: 'Alice',
+      senderGroupNickname: 'A',
+      timestamp: 1,
+      type: 0,
+      content: 'hello chatlab',
+      platformMessageId: 'message-1',
+      replyToMessageId: 'message-0',
+    })
     assert.deepEqual(chatlab, chatlabTs)
 
     const weflowSource = source('weflow.json', {

packages/web-runtime/src/import/wasm-parser.ts

@@ -99,7 +99,7 @@ export async function parseWithWasm(
       const batchJson = parser.take_batch_json(batchSize)
       if (batchJson === undefined) break
       const batch = JSON.parse(batchJson) as WasmNativeMessage[]
-      messages.push(...batch.map((message) => mapMessage(message, formatId)))
+      for (const message of batch) messages.push(mapMessage(message, formatId))
       options.onProgress?.({
         stage: 'parsing',
         progress: summary.messageCount === 0 ? 1 : messages.length / summary.messageCount,
@@ -218,21 +218,32 @@ function mapMembers(
 }
 
 function mapMessage(message: WasmNativeMessage, formatId: BrowserWasmFormatId): BrowserParsedMessage {
-  const mapped = {
-    platformMessageId: optionalString(message.platformMessageId),
+  const platformMessageId = optionalString(message.platformMessageId)
+  const senderGroupNickname = optionalString(message.senderGroupNickname)
+  const replyToMessageId = optionalString(message.replyToMessageId)
+  if (formatId === 'weflow') {
+    return {
+      platformMessageId,
+      senderPlatformId: message.senderPlatformId,
+      senderAccountName: message.senderAccountName,
+      senderGroupNickname,
+      timestamp: message.timestamp as number,
+      type: message.messageType,
+      content: message.content ?? null,
+    }
+  }
+
+  const mapped: BrowserParsedMessage = {
     senderPlatformId: message.senderPlatformId,
     senderAccountName: message.senderAccountName,
-    senderGroupNickname: optionalString(message.senderGroupNickname),
     timestamp: message.timestamp as number,
     type: message.messageType,
     content: message.content ?? null,
-    replyToMessageId: optionalString(message.replyToMessageId),
   }
-  if (formatId === 'weflow') {
-    const { replyToMessageId: _replyToMessageId, ...weflowMessage } = mapped
-    return weflowMessage
-  }
-  return compact(mapped)
+  if (platformMessageId !== undefined) mapped.platformMessageId = platformMessageId
+  if (senderGroupNickname !== undefined) mapped.senderGroupNickname = senderGroupNickname
+  if (replyToMessageId !== undefined) mapped.replyToMessageId = replyToMessageId
+  return mapped
 }
 
 function optionalString(value: unknown): string | undefined {